Swallenia alexandrae

HABIT Perennial. Rhizomes elongated. Culms erect; 20–40 cm long. Leaves distichous. Leaf-sheaths longer than adjacent culm internode. Ligule a fringe of hairs; 1 mm long. Leaf-blades 4–14 cm long; 3–6 mm wide; coriaceous; stiff; glaucous. Leaf-blade surface ribbed. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 4–10 cm long. Primary panicle branches bearing 1–3 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–7 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 10–15 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 9–14 mm long; 1 length of upper glume; membranous; without keels; 7–11 -veined. Lower glume apex acuminate. Upper glume elliptic; 9–14 mm long; 1.1–1.75 length of adjacent fertile lemma; membranous; without keels; 7–11 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma elliptic; 8 mm long; chartaceous; without keel; 5–7 -veined. Lemma midvein ciliate; hairy below. Lemma surface villous; hairy on veins. Lemma apex acute; mucronate. Palea 2 -veined. Palea surface villous; hairy on flanks. Palea apex with excurrent keel veins. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 3.5 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 4 mm long. Embryo 0.66 length of caryopsis. Hilum punctiform.

DISTRIBUTION North America: southwest USA.

NOTES Eragrostideae. WDC.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.